Beverages can be dispensed in a variety of ways, such as in single serving containers like bottles and cans, or in bulk such as from a gallon jug, or even larger, from a soda fountain or large beverage container with a faucet. Examples of the latter case include large tea urns and large insulated water jugs. These are typically provided with a faucet (or tap or spigot of some type) that has a valve member that can be pulled, squeezed or pivoted to selectively open (and close) a valve. Such action allows the beverage to flow freely from the container and into a waiting cup positioned directly below the faucet.
In some applications, the beverage dispensing system includes a beverage container, a faucet and a plastic and disposable liner (a bag with an opening at the top) disposed inside the container. The liner includes a relatively thin-walled outflow tube connected to and near its bottom by a complementary fitment whereby the lumen (interior passageway) of the tube is in communication with the inside of the bag. When the liner is inserted into the container, the tube—typically made of rubber or a synthetic elastomer—is pushed through a passageway defined in the faucet. The faucet is designed, upon activation of its valve member, to drive a pin or plunger down against the tube and to pinch off the tube, thereby selectively preventing beverage from flowing through the tube.
Typically, the tube first exits the container and extends into the faucet at a zero degree angle (that is, horizontal) and then curves through an angle of about 90 degrees (or less in some embodiments), through and out the end of the faucet where it then points straight down (or nearly straight down) toward a waiting beverage cup. Bending such tubing, usually even a few degrees and without any external constraint, will create a kink, which impedes flow through the tube
To reduce kinking and to maximize flow rate through the tube, the faucet passageway diameter should be as large as possible and the tube's outer diameter should be roughly the same as the inner diameter of the faucet passageway. However, frictional forces between the rubber (or similar material) tubing and the (typically plastic) passageway walls then make it difficult, if not impossible, to push the thin-walled and flexible tubing through the arcing faucet passageway. So, the tubing's outer diameter (for a given faucet inner diameter) is reduced enough to reduce frictional contact between tube and passageway walls to enable the tube to be pushed through the arcing passageway. Now, because the tubing's wall thickness has been reduced (outer diameter reduced, inner diameter unchanged), the tubing will usually kink at one or more locations inside the now larger and arcing passageway. Thus, the wall thickness must be increased to resist kinking, which means the inner wall diameter is reduced, thus reducing flow rate, and so on.
One attempt to address this kinking effect is described in U.S. Pat. No. 8,757,441 to Smith, which teaches making the faucet passageway in an oval rather than circular shape, the narrowest dimension of the oval being closer to the outer diameter of the tube. Even if this oval shape does reduce kinking, it still generates frictional resistance to pushing the tube through the passageway.
Another way to reduce the frictional resistance is to make the tube and/or faucet of different materials and/or to coat the tube and/or faucet passageway walls with materials that reduce the coefficient of friction therebetween. These configurations have been made, but they are prohibitively more costly.
What is needed is an improved beverage dispensing system with container, liner and faucet.